1. Field of the Invention
The present invention relates to a wrench with an anti-slipping function.
2. Description of the Related Art
Taiwan Utility Model No. M240308 discloses a ratchet wrench having an anti-slip protective jacket. The ratchet wrench comprises a body having a handle on which the anti-slip protective jacket is integrally formed by injection molding. The protective jacket includes a regular anti-slipping section consisting of a plurality of regular protrusions and recessions for anti-slipping purposes. However, the end portions of the handle adjacent to two ends of the body are not provided with the anti-slipping protrusions and recessions.
In the beginning of tightening of a fastener that requires smaller torque, an end of the body is coupled with the fastener and a user can rapidly turn the fastener by grasping an end portion of the handle with the thumb and the index finger of one hand and moving the wrench back and forth. In the final stage of tightening that requires larger torque, the user can hold the other end portion of the handle distal to the fastener to provide larger torque. However, since the end portions of the handle are not provided with the anti-slipping structure, the user's hand is liable to slip and might be injured when impinging an object.
Further, the regular protrusions and recessions formed in the intermediate portion of the handle extend in a direction transverse to the extending direction of the handle such that the regular anti-slipping section merely provides an anti-slipping effect when a longitudinal force is applied. More specifically, the anti-slipping effect is limited, as the user's hand moves in a direction transverse to the extending direction of the handle while operating the handle.
Even if the jacket extends to the end portions of the handle, the jacket made of rubber or plastic is liable to be scraped and damaged when impinged upon a metal tool. The anti-slipping effect degrades accordingly. Further, the jacket deteriorates when coming in contact with oil, leading to damage to the jacket and loss of the anti-slipping function.
In another embodiment disclosed in Taiwan Utility Model No. M240308, the wrench body includes upper and lower grooves for coupling with protrusions of the jacket. In a further embodiment disclosed in Taiwan Utility Model No. M240308, the wrench body includes through-holes, and an upper jacket has projections extending through the through-holes for snapping engagement with engaging holes in a lower jacket. In still another embodiment disclosed in Taiwan Utility Model No. M240308, the wrench body includes screw holes, and screws are extended through holes in upper and lower jackets and into the screw holes of the wrench body. These designs result in an increase in the manufacturing cost while failing to provide the required anti-slipping effect.